The present invention relates to a vehicle-body front structure of a vehicle.
An automotive vehicle, as a vehicle, comprises a pair of right-and-left side frames extending longitudinally at a vehicle-body front portion and a bumper beam extending in a vehicle width direction and attached to respective front ends of the pair of right-and-left side frames. Further, the automotive vehicle may be equipped with a protecting member including a stiffener (which may be called a lower bumper beam) extending in the vehicle width direction which is provided below the bumper beam in order that when a vehicle collides with a front obstacle, especially when a pedestrian's leg portion hits, the obstacle is restrained from coming in below the vehicle-body front portion. As the above-described protecting member, a structure which can effectively absorb collision energy (impact) in the collision with a properly short stroke is disclosed in Japanese Patent Laid-Open Publication No. 2009-179139.
Herein, in a case in which the front obstacle is a pedestrian, the protecting member collides with the pedestrian's leg portion. In this case, preventing the obstacle from coming in below the vehicle-body front portion can be achieved by the protecting member itself. Further, restraining partial deformation of the obstacle (an injury of the leg portion, for example) may be provided by energy absorption through deformation of the protecting member. Particularly, the protecting member may collide with a lower portion of the pedestrian's leg portion (a portion below a knee), whereas a front end portion of an engine hood (a bonnet) of the vehicle collides with an upper portion of the leg portion above the knee, so that the collision energy (impact) may be properly absorbed through its dispersion at the upper and lower portions of the leg portion.
Meanwhile, in a vehicle, such as a sports car, in which the level of a front end of the engine hood (or a front end of a vehicle-body exterior member positioned in front of the engine hood) is considerably low, it may be difficult to absorb the collision energy at a higher level than the knee of the leg portion of the pedestrian as the obstacle, for example. Particularly, in a case in which the obstacle is the pedestrian, it may be preferable that the pedestrian be flicked up onto the engine hood after the collision.
According to the protecting member of the above-described patent document, however, it may be difficult to obtain both the energy absorption sufficient for the partial deformation restraint of the obstacle and the flicking-up of the obstacle by means of the protecting member only. Especially, since a load/deformation characteristic showing a relationship of a collision load and a deformation amount of the protecting member of the above-described patent document is configured such that the deformation amount increases substantially proportionally to an increase of the collision load, it may be difficult to satisfy both the sufficient energy absorption in the collision and the flicking-up of the obstacle by means of the protecting member only.